Particularly for users of R that have some experience with other programming languages (e.g. Python, ...), one of the most difficult parts of getting started with R is understanding what sorts of objects there are in R and how these objects behave. As the lesson points out, "Everything in R is an object". However, unlike in other programming languages, users typically interact with primitive data types only through the (complex) data structures of atomic vector, list, etc.

This contrasts with how many students typically first encounter the idea of "data types". In C++/C#/Java/etc. students might first learn int i = 0;. We don't typically discuss i as a "data structure" and to do something like add i to an array would not work. However, in R you can do things like c(1:10) + 1

I would be happy to work on this issue, in particular by adding some information from the Data Strcutures chapter of Hadley Wickham's Advanced R.

Note: I stumbled across this repository/project through a Google search for "r data types vs structures". It is the first result for this search query as of 5/4/2019!

This comment has been minimized.

Here are some suggestions I believe could easily be incorporated without introducing more concepts and tools.

Addition to first objective

Expose learners to the different data types in R and show how these data types are used in data structures.

Addition to second key point

R's basic data structures include [...]. Some of these structures require that all members be of the same datatype (e.g. vectors) while others permit multiple datatypes (e.g. lists).

This information is presented implicitly in the lesson, which describes how to work with some data structures and restrictions that go into making them. Clarifying these points in the objectives/key points will be reinforcing what is already there.

Other things

I could also look over doing some edits to some wording in the text, e.g.

Make objectives consistently start with verbs:

Getting familiar -> Get familiar with the different...

the second paragraph in "Understanding Basic Data Types in R":

Data structures are very important to understand because these are the objects you will manipulate...